Five boys and five girls from a line. Find the number of ways of making the seating arrangement under the following condition:

Explanation

(i) Boys and girls are alternate.

There can be two posiibilities.

(a)First boy then girl then boy then girl and so on.

It can be done in `5!*5!` ways.

(b) First girl then boy then girl then boy and so on.

It can be done in `5!*5!` ways.

So, for this, there can be `2*5!*5!` ways.

Also, we can write, `(5!)^2 +(5!)^2`

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